Heat-economizer.



No. 659,065. Patented Oct. 2, I900. J. B. HOUSTON.

HEAT ECONUMIZER.

A (Application filed July 11, 1900.)

(No Model.) 2Sheats8heet l.

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UNITED STATES PATENT OFFICE.

JOHN BROADFOOT HOUSTON, OF VANCOUVER, CANADA.

H EAT-ECONOM IZER.

SPECIFICATION formingpart of Letters Patent No. 659,065, dated October2, 1900.

Application filed July 11, 1900. Serial No. 23,259. (No model.)

To all whom it may concern:

Be it known that I, JOHN BROADFOOT Hous- TON, a citizen of the Dominionof Can ada, residing at Vancouver, in the Province of British Columbia,Canada, have invented a new and useful Heat-Economizer, of which thefollowing is a specification.

My invention particularly relates to that form of economizer wherein theair for combustion, whether in forced or induced draft, is heated duringits passage to the furnace by being brought in conductive proximity tothe heated gases from the same, which haviug parted with their eificientheat to the boiler are passing through the uptake to the smoke-stack.

My aim has been to design an apparatus which shall be thoroughlyefficient in deriving all available heat from the waste gases from thefurnace; wherever possible to jacket the uptake-fines with the incomingair, so as to expose a cool surface to the boiler-room; to so constructit that the uptake-passages can be readily cleaned by the means providedfrom any accumulation of soot or furnacedust, and to make it extremelysimple and practical in construction. I attain'these objects by themeans illustrated in the accompanying drawings, in which 7 Figure 1 is asectional View of the economizer as applied to a boiler of the ordinarymarine type, taken on a line a a in Fig. 2. Fig. 2 is a verticalcross-section of the same on the line b b in Fig. 1. Fig. 3 is ahorizontal cross-section on the line (i d in Fig. 1. Fig. 4 is anenlarged detail, being a section through the uptake-door on the line 0 cin Fig. 5, which shows my means of jacketing the same and also the meansby which I free the interior surfaces of the uptake from soot, &c. Fig.5 is a front elevation of the door.

In the drawings, B represents the front or furnace end of a boiler ofthe ordinary marine type, of which E are the furnaces and T thereturn-tubes, from which the products of combustion pass into the uptakeU, as indicated by the arrows. In the uptake U and just above the levelof the boiler-tubes T, I place the tubes 1 of my economizer, passinghorizontally across the width from side to side of the uptake.Surrounding the front,

back, and sides of the uptake-casing 2 and forming a jacketed wall forthe same up as far as the base of the smoke-stack S is an outer casingor jacket 3. This jacket-casing 3 is carried down below the bottom ofthe uptake-flue and connects to a furnace-front of suitable design toinsure regulated admission of the heated air to the furnaces. Near theupper part of this jacket is a passage 4, by which the air-supply to thefurnace flows, and directly in line with this is a passage 5, connectingthe front and back jackets through the uptake. (See Figs. 1 and 2.) Thisconveys a portion of the air-supply entering by the inlet 4 to the backjacket by the short direct pipe 5, exposed to the heat in the up take,which pipe incidentally braces the front and back walls of the uptake.The side jackets are so constructed that the parts opposite theeconomizer-tube plates are removable,

giving access to the tubes.

casing of the back jacket to the center of the tube-plate vertically upto above the top row of tubes and thence to the outer casing of thefront jacket. A division 9 (see Fig. 3) cuts the right-side jacket offfrom the front one. These divisions are riveted in where convenient, asin 7 and 9; but in 6 and 8 the casings 2 and 3 are drawn up togetheragainst the edges of the division-plate by the screwbolts at intervals,as at 6* and 8". The outer and inner casings of the jacket are tiedtogether at intervals by bolts'3 to' prevent bulging or buckling of theflat surfaces. The

effect of these partitionscis to divide the incoming air for combustionentering by the passage 4, so that part flows across the front jacket tothe left side through the front half of the horizontal tubes and thencedown the front half P of the right-side jacket to the naces derive theirsupply. The remaining portion of the incoming air passes through thepipe 5 to-the back jacket, across it to the right side, and, passingthrough the back half of the horizontal tubes, goes down the back half Pof the left-side jacket to the furnaces. By this arrangement where twoor more furnaces are used I am enabled to get an equal distribution ofthe air to the furnaces, and I also insure that each stream is of thesame temperature. The arrangement is also one which enables a simple andeminently practical construction to be adopted.

In boilers having any system of forced combustion the uptake gases areso hot that where they impinge on such a surface as an uptake-door,which gives access to the boilertubes and therefore receives the directimpact of the gases as they come through the tubes T, any ordinarymethod of protecting the same by means of baffle-plates or nonconductivelinings are totally ineflicient, and under such conditions the life ofthe door is not only extremely short, but the door is cumbersome andheavy and with the best of such protection transmits a very considerableheat. to the boiler-room. I obviate these objections by constructing myuptake-door with an ample air-space between two "walls and providing forthe circulation of air therein. The door is composed of two plates, aninner 10 and outer l1, flanged around their edges, as shown, and rivetedthrough these flanged edges one within the other, so as to leave anample intervening space. Such con- Struction offers an easy method ofriveting, while the flanges impart rigidity to the door and offer aconvenient means of making a tight seat-joint on the front face of theuptake-flue. Distance-pieces are riveted between the plates to stay theflat surfaces against buckling. The doors are hung on hinges andfastened shut in the usual manner with such doors.

I secure circulation of air through the doors in the following manner:In the base of the front uptake-jacket, just above each door, anaperture 15, of suitable size, is cut and another to correspond in thetop of the outer flange of each door. A light casting 13, having anaperture 14 cored therein to correspond with those of the door andjacket-base, is bolted on the top flange of the door, so that theopenings correspond, and the top face of this casting terminates in aplane proximate to the lower surface of the angle-iron which formsthejacket-base. Agroove runs around the opening in this face of thecasting, in which packing 16 is placed, so that when the door is closedand fastened such packing will form an air-tight closure around theopening. A similar opening 17 is cut in the inner casing of each door inproximity to the lower flanged edge, and in the bottom plate of theuptake-flue an opening is cut to correspond therewith. A casting 18 isattached to the latter, having a port or passsage 19 cast therein tocorrespond with the openings-in the flue bottom and door. The passage inthis casting is carried around to the plane of the inner plate of thedoor when closed, and around the opening is a groove wherein packing 20is placed, so that when the door is shut and fastened an air-tightclosure is made around the passage. Thus a com m u nication is made bywhich the incoming air can flow from the jacket through the door andinto the hotair cham her adjacent to the furnaces. The heat is carriedaway from where it is useless and injurious and conveyed to where it isbeneficial in aiding complete combustion of the fuel.

When furnace gases and smoke come in contact with the cooling-surfacesof the uptake jackets and tubes, they will readily condense and adhereto them as soot, and it is imperative that these surfaces be kept freefrom such deposits or the possible economies of such a system as thisare lost, for such deposits not only impede the draft by restrict,- ingthe passages, but'as non-cond uctors preventthe conveyance of heatthrough the tubes and plates to be taken up by the air for com bustion.To obviate this objection, I have introduced a system of cleaning theotherwise inaccessible parts which is simple in construction, can bereadily used without opening the uptake-doors or stopping the stoking oruse of the furnace, and is thoroughly elfective. I introduce at thecenter of the bottom of the group of economizertubes, just above thebottom row, a steampipe 21. This pipe is plugged at the inner end and isprovided with a series of perforations 22, corresponding with thesurfaces of the uptake and the spaces between the tubes. The pipe passesthrough the plates of the jacket and uptake, a drilled fit, and, beingprovided with a packed gland 23 outside the casing, can be readilyrotated by means of the lever 24. Steam being turned into the pipe 21,it is rotated through a sufficient are by means of a handle 24, and theissuing steam from the perforations 22 sweeps all deposits adjacent tothe planes of its rotating jets, and the soot is carried up the stack bythe draft.

Having now described my invention, what I claim as new, and desire to beprotected in by Letters Patent, is

1. In an economizer of the class described; in combination with anuptake-flue connecting the boiler-tubes with the smoke-stack; a numberof tubes passing horizontally across such uptake; an air-tight jacket orcasing surrounding the front, back and sides of the uptake and extendingfrom the base of the smoke-stack down to the furnace front; means forconveying the air for combustion to within such jacket; an air-passageconnecting' the front and back jacket through the uptake;division-plates or partitions in the air-tight jacket dividing thegroups of tubes vertically into two sections, and so arranged that theentering air shall fiowin two streams in opposite directions through theback and front sections of the vertically-divided group of tubes andthereafter pass to the furnaces, substantially as and for the purposesset forth.

2. In an economizer as described; in combination with an uptake-flue; ajacket surrounding the front, back and sides of the same; an uptake dooror doors composed of an inner and outer casing, which being flangedaround their edges and riveted together one within the other, aroundsuch flanged edges forming the joint of the opening the door is designedto close; an air-space retained between the inner and outer casing ofthe door and means whereby air may be circulated within such doorair-space, when the door is shut and fastened, as and for the purposesdescribed.

3. In an economizer as described, in combination with an uptake; ajacket surrounding the same; an aperture in the base of such jacket just over such uptake-door; an u ptakedoor having an inner and outercasing and an air-space therebetween; an aperture in the u pper flangeof the outer casing to correspond 'with one in the base of the jacket; acasting surrounding such opening fastened to the door and carried upclose to the aperture in thejacket-base; a groove surrounding theopening in the casting and packing therein that joints around theaperture in the base of the jacket when the door is closed and fastened, and forms an air-tight closure surrounding the passage; anopening in the inner casing of said door in proximity to the lowerflanged edge; a corresponding opening in the bottom plate of theuptake-flue; a casting attached to the bottom plate of the up take-fluehaving a port or passage in it to correspond with the aperture, suchpassage and casting to be carried up and around until its face isadjacent to and in a proximate plane with that of the inner casing ofthe door; a groove surrounding such opening and a packing in the grooveto form an air-tight joint around the opening in the door-casing whenthe door is shutand fastened, all substantially as and for the purposesset forth.

4. In an economizer having air-tubes passing across an uptake-flue and ajacket surrounding the same, in combination; a steampipe closed at itsinner end and passing through the jacket into the uptake in a line atright angles to the direction of the airtubes and in a parallelhorizontal plane, said pipe to be capable of rotation in thejacket-casings; perforations in such steampipe between each vertical rowof tubes and adjacent to the front and back plates of the uptake; agland-packed attachment to the steam-service exterior to the economizerand a handle for rotating the same, substantially as and for thepurposes described.

JOHN BROADFOO'I HOUSTON.

Witnesses:

W. G. IRA THEWEY, ROWLAND BRITTAIN.

